Extensible electric conductor



May 1l, 1948. F. J. M. DANSARD 2,441,236

i EXTENSIBLE ELECTRIC -CONDUCTOR Filed Nov. 6, .1946

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Patented May 11., 1948 EXTENSIBLE ELECTRIC CONDUCTOR Flix Jean Marie Dansard, St.-Chamond, France Application November 6, 1946, Serial No. 708,013 In France November 14, 1945 2 Claims. l

In my prior French Patent No. 828,776 of January 5, 1937, and U. Si. Patent specification 2,143,649, I have'described an extensible electric conductor constituted by a yielding string and a yielding strip connected thereto through the cooperating ends of the string and strip and also at regularly spaced points through the length of said string and strip. The strip is not extensible and serves as a support for the electric leads while the string is yieldingly extensible and carries no electric lead. In this prior conductor, the yieldingly extensible string passes through the strip at regularly spaced points of its length considered in its non-extended state, whereby the non-extensible strip is adapted to be folded after the manner of an accordion or of a concertina over the string and is thus permanently connected with the latter at the passages provided therefor through it, which allows these mutual displacements and an easy separation between them.

Now it has been found in use that the inextensible strip coils round the elastic string passing through the buttonholes provided in the strip and this objectionable coiling is particularly apparent when the string is cylindrical. Consequently the conductor assumes an unpleasant appearance when it has been extended and rel turns into its original shape. My present invention has for its object to remove this undesired appearance by preventing the strip from possibly rotating round the elastic string.

To this end, I provide the passage through the buttonholes of the non-extensible strip carrying the electric leads of two elastically extensible strings in a non-extended state, said two strips being arranged in parallelism and having their ends in bearing relationship with the outer surface of the last fold of the non-extensible strip. I have shown by way of example in accompanying drawings a preferred form of execution of my invention.

Fig. 1 shows one end of the extensible electric conductor.

Fig. 2 is a cross-section through line 2-2 of Fig. 1.

Fig. 3 is a plan view of the inextensible strip carrying the electric leads.

In the electric conductor illustrated, the strip or ribbon 2 serves as a non-extensible support for the electric leads which p ass out of said strip as shown, three in number, at II, I2, and I3, said leads being distributed throughout the breadth of the strip while suitable care is exercised for obtaining isolation as required by the conditions of use.

Preferably in the medial part of the strip there are provided at regular or irregular spacings openings or buttonholes 3.

The ribbon or strip 2 whether plaited, woven or knitted is carefully folded, the number of folds being equal to half the number of buttonholes 3, which latter are distributed after folding along two lines A and B. There is then inserted inside the buttonholes along either line an elastic string I4 vwhich may be same for both lines, when it is caused to form a loop in contact with the last fold at one end of the conductor while at the other end the two free strands I5 and IB of the elastic string I4 are bound together and if required concealed under a binding concealing means I'l bearing against the outer surface of the extreme fold I 8.

It is apparent that when drawing the plaited ribbon 2, the latter will expand and when released it will resume its original folded position through the action of the double elastic string I4. This return movement is performed without the strip 2 coiling by reason of the presence of the tWo parallel elastic strings which prevent any rotation of the strip such as that occurring around a single elastic string. Obviously my invention is by no means limited to the simple form of execution which has been more particularly described and on the contrary it covers all the modi- 'cations thereof more particularly as concerns the distribution of the buttonholes and the shape of the elastic string for which a spring may also be substituted, insofar as said modifications fall within the scope of appended claims.

What I claim is:

1. In an extensible electric conductor comprising a folded supporting strip of non-extensible material and provided with a series of openings located at the folds and distributed throughout its length, electric wires carried by said strip and adapted to follow the deformations thereof and two elastic strings passing respectively through the two buttonholes of all the even and of all the odd pairs of successive buttonholes at the folds to either side of the folded strip, said strings 3 lying in parallel relationship in their unextended inoperative state and bearing against the outer surface of the extreme folds of the strip through their corresponding ends for allowing the simultaneous longitudinal deformations of the strings and of the strip arrangement.

2. An extensible electric conductor comprising a folded supporting strip of non-extensible material and provided with a series of openings located at the folds and distributed throughout its length, electric wires carried by said strip and adapted to follow the deformations thereof and a looped string the two strands of which pass respectively through the two buttonholes of all the even Aand of all the odd pairs of successive buttonholes at the folds to either side of the folded strip, said strands lying in parallel relay tionship in their unextended inoperative state and the looped end of the string bearing against the outer surface of the extreme fold at one end of the strip and means for causing the free ends of the strands to bear against the outer surface of the other extreme fold.

FLIX JEAN MARIE DANSARD.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number `Name Date 1,686,678l Burke Oct. 8, 1928 y2,143,649 Dansard Jan. 10, 1939 

